1. Field of the Invention
The present invention relates to a movable bio-scaffold and a method for constructing the same. More particularly, the present invention relates to a bio-scaffold which can move to a target site under the control of an external magnetic field, and a method for constructing the same.
2. Description of the Related Art
In recent years, great progress has been made in the bioengineering field, particularly, tissue engineering. Tissue engineering is an interdisciplinary field that applies the principles of engineering and life sciences toward the development of biological substitutes that restore, maintain or improve tissue function or a whole organ, based on the understanding of relationship between structures and functions of tissues.
In spite of the rapid development of medical engineering to a high level, organ transplantation, which is for the purpose of replacing damaged or absent organs, which frequently occur, still remains difficult, with various problems including high cost, deficiency of donors, and side effects associated with the use of immunosuppressants.
The development of artificial organs or the regeneration of tissues, based on tissue engineering, has been emerging as a new approach to organ transplantation. Tissue engineering is fundamentally focused on the implantation of a cell-scaffold complex to a patient which is fabricated by taking a necessary tissue from the patient, isolating cells from the tissue, and culturing the cells on the scaffold.
For use in biological application, the scaffold should meet various requirements as well as safety in the body. A scaffold must be formed of a material helpful for the attachment, growth, and differentiation of cells, and a porous structure must be formed across the scaffold so that cell growth and tissue regeneration can be facilitated therein. Further, high interconnection should be established among pores of the porous structure. In addition to having biocompatibility, a bio-scaffold should be of porosity so that it provides a large surface area to facilitate the integration of cells to be implanted into a tissue. According to the site where to apply, the bio-scaffold may be formed of a biodegradable material. Most of currently used bio-scaffolds are applied mainly to the regeneration of the bone, the skin, and organs. Morphologies and pore sizes of the bio-scaffolds are determined according to the cells and tissues to be implanted thereinto. Porosities, pore sizes, and three-dimensional interconnection of multiple spaces of bio-scaffolds are very important factors because they have great influence on the establishment of new tissues in the bio-scaffolds. A porous structure is necessary for carrying a sufficient number of cells while an interconnected porous syntax is responsible for the diffusion of nutrients.
Research and development has recently continued to be directed toward the preparation of bio-scaffolds which can be stably used for the therapy and regeneration of tissues.
Conventional scaffolds are, however, disadvantageous in terms of insertion into the body localization to a target site. For example, they are inserted directly into the body and localized at a target site, mostly with the aid of surgery and mechanical instrument, which may give rise to the likelihood of infection and injury during the insertion. In addition, a limitation is imposed on the application of conventional scaffolds to local sites difficult to approach, or sites which become in danger upon external exposure, such as vessels and cerebral tissues.